If you want "common" names like Dell, Sony, Compaq, Packard Bell/HP, Toshiba, etc then go for them. Alienware is unique, not a lot of people have them, you're sure to stand out as well as having a very good looking laptop + a very powerful one.
I felt the same as you did 4 days ago before I ordered mine. But eventually I just brought it, and to be honest, reading all the comments around here, it actually is worth it.
Another way to look at it ; do you really need a POWERFUL laptop? If you only need it to work on [word process, database/spreadsheets], check a few e-mails and surf the web, an AW isn't really needed.
I don't know how old you are, but it's like with buying a car. Most people I know seem to opt for FASTER cars. Is THAT really needed? You cannot drive fast on todays roads anyways without getting 20 cop cars trying corner your ass down. It's the same with anything else in this argument, expensive clothes or normal clothes/shoes? McDonalds or some high reptutation food restaurant?